SIMI VALLEY, CALIF. — See that image?

If you didn’t catch it tonight from the CNN-televised Republican presidential debate from the Ronald Reagan Presidential Library, chances are decent that you’ll catch it on replay in the coming years, when some pundit or other recaps all the classic moments in U.S. presidential debate history.

The moment came about after debate moderator Jake Tapper asked the field if front-runner Donald Trump could be trusted with nuclear triggers. Trump himself said yes. Sen. Rand Paul attacked Trump’s fitness to take command of the country. Trump spoke highly of his temperament and ripped Paul’s fitness to stand on the debate stage; Paul knocked him for his “visceral response to attack people on their appearance: short, tall, fat, ugly. My goodness, that happened in junior high!” As all this happened, some producer at CNN thought it would be a great moment to go to a split-screen format.

That was a very good decision.

Split screens, of course, are standard stuff at CNN and other cable outlets. So standard, they’re often overused — like when an anchor and a commentator are in the same location, yet separated by a split screen. They just so happen to be a fitting accoutrement for CNN’s strategy in this session. Tapper made clear beforehand that he wasn’t seeking one-one-one clashes between himself and each of the candidates. Better to have these folks joust with one another. With 11 candidates onstage, you’ve got to limit the visual madness. Capturing Donald Trump’s petulant grimaces is a good start.